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Photon Energy Dependence of the 1{sigma}{sub u}/1{sigma}{sub g} Intensity Ratio in Carbon 1s Photoelectron Spectroscopy of Ethyne

Journal Article · · Physical Review Letters
;  [1]; ;  [2]; ;  [3];  [4]; ;  [5]
  1. Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003 (United States)
  2. Physics Department, Western Michigan University, Kalamazoo, Michigan 49008 (United States)
  3. Advanced Light Source, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)
  4. Keuka College, Keuka Park, New York 14478 (United States)
  5. Department of Chemistry, University of Bergen, N-5007 Bergen (Norway)

High-resolution measurements of the C 1s photoelectron spectrum of ethyne (acetylene) at photon energies between 297 and 348thinspthinspeV have been analyzed to give the energy dependence of the relative cross sections for ionization of the 1{sigma}{sub g} and 1{sigma}{sub u} orbitals. The 1{sigma}{sup {minus}1}{sub u}/1{sigma}{sup {minus}1}{sub g} intensity ratio is greater than 1 at the lowest photon energies but reaches a minimum of about 0.6 between 315 and 320thinspthinspeV. These results can be understood in terms of the effect of shape resonance on the ionization cross section and provide quantitative information on the position and magnitude of such resonances. {copyright} {ital 1999} {ital The American Physical Society}

OSTI ID:
307279
Journal Information:
Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 6 Vol. 82; ISSN 0031-9007; ISSN PRLTAO
Country of Publication:
United States
Language:
English